| 摘要 |
The invention relates to a control device for operating a load circuit comprising at least one electric motor. The control device has a control stage, which generates a pulse-width modulated control signal, and has a power stage, which supplies power to the load circuit and which is provided with an electronic switch that is controlled by the pulse-width modulated control signal. The control device also has a free-running element, which is connected in parallel to the load circuit, and has a blocking monitoring, which produces a measuring disable interval by suppressing at least one enable interval of the pulse-width modulated control signal. The voltage in the load circuit is monitored during the measuring disable interval, is compared with a limit value, and a blockade state signal is generated based on this comparison. The aim of the invention is to improve a control device of the aforementioned type whereby enabling a differentiated analysis of the voltages occurring in the measuring disable interval. To this end, the invention provides that, for monitoring at least two electric motors connected in parallel in the load circuit, the blocking monitoring executes a test cycle with at least one measuring cycle in which a voltage sampling ensues at different defined points in time after the start of at least one measuring disable interval, and the voltages determined in the load circuit during voltage samplings are compared with at least one limit value. |
